In business, use has recently been made of an IP telephone system in which a plurality of IP telephone devices (IP telephone terminals) are managed by a main device.
Using a database about the managing IP telephone devices in the IP telephone system, the main device, for example, manages outside-line and extension outgoing and incoming calls and offers a telephone book function and a speed dial function. For the IP telephone system using such a main device, an administrator (creator) or the like is required to set many configurations when introducing (setting up) the IP telephone system, adding an IP telephone device, changing configurations of the IP telephone device, or the like.
Techniques about IP telephone systems are described in Patent Documents 1 and 2.
Patent Document 1 describes IP telephone devices each having an interface section for use in connection to a LAN (Local Area Network) and an IP telephone system to which such IP telephone devices are connected. Patent Document 1 describes that network setting of the IP telephone devices, registration of the IP telephone devices to a managing device (main device), and initial setting (internal setting) of the IP telephone devices are essential (see paragraphs [0003] to [0005]).
Patent Document 2 describes an IP telephone system in which an IP telephone device automatically acquires network configurations from a server group and sets the acquired network configurations. Patent Document 2 describes a main device that accommodates a plurality of IP telephone devices and conducts exchange with an outside line.
The IP telephone systems described in Patent Documents 1 and 2 both assign an IP address to each IP telephone device using the DHCP (Dynamic Host Configuration Protocol). On the other hand, there is currently an IP telephone system that uses fixed IP addresses without using the DHCP.    Patent Document 1: Japanese Unexamined Patent Application Publication (JP-A) No. 2005-277694    Patent Document 2: Japanese Unexamined Patent Application Publication (JP-A) No. 2006-339803